This invention relates to special purpose hand tools for mobile equipment, and specifically to tools for use in the lubrication of automotive speedometer cables and the like.
Flexible cable assemblies are used in many applications in the automobile, aircraft, boating and farm equipment industries for controlling equipment or transferring power. One specific application is a speedometer cable which transfers rotational motion from a small shaft on a transmission to another shaft on a speedometer.
These cables are typically made of fine flexible rod reinforced with a wire winding and operate within an outer protective casing which performs the additional function of acting as a guide member. The cable rotates or otherwise moves within the casing and must be lubricated. If no lubrication is present, the friction created between the cable and the casing causes a binding or hopping operation of the cable and eventually the cable breaks.
The need to relubricate speedometer cables is quite common in the automotive industry, and especially with new cars produced on mass production lines with high-speed equipment and components supplied from independent suppliers which very often undergo long periods of storage before use. On many new cars the speedometer cables are very often installed with the lubrication insufficiently applied or partially dried out from a long period of storage. It is very often necessary to lubricate speedometer cables after only 10,000 miles of use.
With the modular design of automobiles and the compact assembly and sub-assembly of dashboards, engines and other portions of the automobile, it is very often quite difficult if not impossible for a mechanic to manipulate equipment under the dashboard or in the engine compartment to perform such duties as lubricating a speedometer cable. The dashboard end of a speedometer cable very often is difficult to access without substantially dismantling the dashboard and instrument package. This operation often takes more than one shop hour of labor time.
It is desirable to lubricate the speedometer cable from the transmission end thereby permitting the mechanic to break the cable loose from the transmission and force grease up the cable from that end. This process can eliminate more than one hour estimated shop time which it presently takes to dismantle the dashboard and instrument package. However, forcing grease into the transmission end of the speedometer cable does not do a sufficient lubrication job in itself as the grease is reluctant to walk up the cable and thereby the uper half of the cable is not lubricated. When excessive pressures are exerted on the grease the cable often bursts.
A number of cable lubricating tools have been provided in the prior art. These, however, have been devices which merely provide a sealed grease coupling to one end of the cable for forcing grease into that end of the cable. With such tools, the grease is able to travel only short distances along the cable.
Dannels, U.S. Pat. No. 3,268,032, provides a flexible cable lubrication tool comprising a coupling member 34 for joining a standard ball type grease fitting to the end of a flexible cable. A standard alemite grease fitting is then coupled to the ball type fitting for forcing grease into the end of the cable.
Self, U.S. Pat. No. 3,283,854, provides a cable lubricating tool which may become part of and may be permanently coupled to a cable. This lubricating tool includes a casing 21 which is fitted about a special tapered cable end structure 12. A tube 42 is fitted with a ball type grease fitting 46 for introducing grease into the casing 21 and thereby the cable from the side thereof and about the cable. The cable remains in its normal operational hook up. This lubricating tool is essentially a clamp-on device for introducing grease into a pocket through which the cable extends to provide a reservoir of grease to lubricate the cable at that point. No structure is provided by Self as part of high tool for mechanically operating the cable in any specific or intended way while applying grease.
Preszler, U.S. Pat. No. 2,515,611 provides a flexible shaft greasing fitting similar to that provided by Dannels. Preszler provides either a female or male cable end coupling housing 1 to which a ball type grease fitting 2 is attached. An alemite type grease fitting connects to the Preszler structure for forcing grease into the end of the cable casing. Preszler uses this structure for lubricating the speedometer cable at the speedometer end thereof, the upper end of the cable.
West, U.S. Pat. No. 2,178,058 provides a speedometer cable lubrication tool which lubricates the cable from the speedometer end thereof. This tool includes a housing 1 into which a speedometer cable end 27 is installed. A greasing block 12 is adjusted to clamp against the cable 27 via the screw 25 adjustment means and provide a pressure seal thereto. Greasing block 12 includes a channel 18 positioned to mate the end of the cable 27 casing. A ball type grease fitting 20 is screwed into the channel 18 which has been threaded on its end. Grease which enters the channel 18 through the fitting 20 is forced into the speedometer end of the cable 27, the upper end of the cable.
Sievenpiper, U.S. Pat. No. 2,681,711 teaches a lubricating device for lubricating the transmission end of a speedometer cable. The Sievenpiper device includes a housing which sealingly engages the transmission end of the speedometer cable by screwing onto the fitting on the transmission end of the speedometer cable. This housing is fitted at its end with a ball type grease fitting. Grease introduced through the ball type fitting travels along a narrow channel to the end of the speedometer cable and is forced into that end of the cable.
Steffen, U.S. Pat. No. 3,884,329 provides a speedometer cable lubricating device for lubricating the transmission end of a speedometer cable. This device operates similarly to the Sievenpiper device for introducing grease into that end of the cable. The Steffen apparatus includes coupling members for coupling to the transmission and of the speedometer cable and a grease fitting member connected to the coupling member.
These tools, while being able to introduce grease or lubrication into the end of a speedometer cable, and even certain ones of them being able to introduce grease into the transmission end of the speedometer cable, do not provide for an adequate lubrication of that cable as the grease is capable of being forced only a short way up the speedometer cable from its bottom end.
What is desired is a speedometer cable lubrication tool which will enable the grease to be carried up the length of the speedometer cable from its transmission end thereby greasing a substantially the entire length of the speedometer cable.
An object of the present invention is to provide a speedometer cable lubrication tool which will mate in sealing engagement with the transmission end of an automotive type speedometer cable.
A second object of the present invention is to provide this lubrication tool with a standard ball type grease fitting for introducing grease into that coupled end of the speedometer cable through the tool.
A further object of the present invention is to provide a means for rotating the speedometer cable with the tool.
A further object of the present invention is to provide this lubrication tool with the capability of rotating the end of the speedometer cable, in its normal direction of rotation, while interjecting grease under normal but not excessive pressures into the transmission end of the cable.